code: def uniq_stable(elems):
      """uniq_stable(elems) -> list
  
      Return from an iterable, a list of all the unique elements in the input,
      but maintaining the order in which they first appear.
  
      A naive solution to this problem which just makes a dictionary with the
      elements as keys fails to respect the stability condition, since
      dictionaries are unsorted by nature.
  
      Note: All elements in the input must be hashable.
      """
      unique = []
      unique_set = set()
      for nn in elems:
          if nn not in unique_set:
              unique.append(nn)
              unique_set.add(nn)
      return unique
  
file_path: catboost/contrib/python/scikit-learn/py2/sklearn/externals/joblib/format_stack.py
imports: import inspect
  import keyword
  import linecache
  import os
  import pydoc
  import sys
  import time
  import tokenize
  import traceback
label_desc: Use image node_id 3 for calling a global function with example usage: uniq_stable(elems) and returns: unique